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Biomedical subjects

R M Perkin

Publications and source records attributed to R M Perkin.

At least 37 records · Page 2Linked to original sources

Retrograde intubation training using a mannequin.

The purpose of this study was to determine the efficacy of a mannequin for training emergency caregivers in the technique of retrograde intubation. This was a descriptive study using duration of time needed for completion of intubation as a measure of success. A cohort of 88 Emergency Medical Service (EMS) personnel included prehospital caregivers, registered nurses, and respiratory care practitioners. Participants were trained in retrograde intubation by modeling. Students practiced before they were tested. Every subject successfully completed intubation on the first timed effort. Subjects performed retrograde intubation in a mean time of 71 seconds (95% confidence interval +/- 4 seconds), with a range of 42 to 129 seconds. It was concluded that retrograde intubation can be taught easily with a mannequin and that this skill can be learned by emergency caregivers by modeling. Bag-valve-mask ventilation can be performed at any time without the need to restart or interrupt the procedure. Retrograde intubation can be introduced as an intubation technique for the difficult airway encountered by EMS personnel.

Adult↗

Proton magnetic resonance spectroscopy in children with acute central nervous system injury.

Single voxel proton magnetic resonance spectroscopy (1H-MRS) was used in 30 infants and children with acute central nervous system injuries to determine the value of changes in specific metabolite ratios in predicting outcome. The mean age of all patients was 38 +/- 52 months and the mean time of study after insult was 7 +/- 5 days. 1H-MRS was determined in the occipital gray and parietal white matter (8 cm3 volume, STEAM sequence with TE = 20 ms, TR = 3,000 ms). Data were expressed as ratios of different metabolite peak areas including N-acetylaspartate (NA), choline-containing compounds (Ch), creatine and phosphocreatine (Cr), and lactate (Lac). Statistically significant differences were observed when patients with good/moderate (G/M) outcomes (n = 17; mean age: 46 months) were compared to patients with bad outcomes (n = 10; mean age: 26 months). NA/Cr and NA/Ch were significantly lower in the bad outcome group (NA/Cr = 1.15 +/- 0.38; NA/Ch = 1.18 +/- 0.52) compared to the G/M group (NA/Cr = 1.41 +/- 0.28, P < .05; NA/Ch = 1.98 +/- 0.81, P < .01). Lactate was present in 80% of bad outcome patients and in none of the G/M group (P < .0001). Using a linear discriminant analysis and combining 4 clinical variables (Glasgow Coma Scale score, initial pH and glucose, number of days unconscious at time of 1H-MRS) allows classification of 94% of patients into their correct outcome group. Use of spectroscopy variables (NA/Cr, NA/Ch, Ch/Cr, presence of lactate) alone correctly classified 81% of patients. The combination of clinical and 1H-MRS variables correctly classified 100% of patients. Our findings suggest that 1H-MRS adds information which, in combination with clinical examination, may be useful in outcome assessment in children with serious acute central nervous system injury.

Acute Disease↗

Intraosseous extravasation complication reports.

We report two cases of severe complications from intraosseous infusions. One child was a sudden infant death syndrome patient who developed severe tissue necrosis after intraosseous placement. The second child was a near drowning who developed a compartment syndrome requiring fasciotomy. Extravasation is a potentially major complication that resulted in these limb-threatening events. Intraosseous infusion remains an important resuscitation modality, but great care must be taken to avoid these results. Strategies for avoiding extravasation are discussed.

Child, Preschool↗

Upper airway resistance syndrome: sick, symptomatic but underrecognized.

Upper airway resistance syndrome (UARS) appears to be underrecognized or at least underreported in the medical literature. We have found that these children may suffer the same, if not more, severe consequences of sleep disordered breathing than obstructive sleep apnea patients. Seventy-five infants and children were age and gender matched from a heterogeneous patient population in Southern California. Each patient underwent clinical polysomnography. Twenty-five patients were in each of three groups. Group one patients were clinician referred to the sleep clinic and were found to be free of significant sleep pathology. Group two patients had UARS. Group three patients had frank obstructive sleep apnea. The three groups differed on respiratory, sleep and snoring parameters. A heuristic is presented to help clinicians tailor their treatment approach and sleep scientists to test the model to aid in the understanding of UARS.

Airway Resistance↗

Respiratory failure complicating rubeola.

We reviewed the charts of 19 patients with the diagnosis of measles who were admitted to the pediatric intensive care unit for respiratory failure requiring intubation and mechanical ventilation. Patients studied were admitted during the period June 1989 to June 1990. The mean age was 19 months (range, 3 to 51 months). The cause for respiratory failure fell into two groups: 47 percent developed pneumonitis and refractory hypoxemia. Patients with pneumonitis and hypoxemic respiratory failure had a 56 percent mortality. An oxygenation index of greater than 40 for 4 h separated survivors from nonsurvivors (oxygenation index = [mean airway pressure x FIo2/PaO2 x 100]). Patients with tracheitis alone all survived. In these patients the organism primarily responsible was Staphylococcus aureus (70 percent). Two of the seven patients with S aureus tracheitis had signs and symptoms of toxic shock syndrome and we subsequently demonstrated toxic shock syndrome toxin 1 in both patients.

Child, Preschool↗

Mojave rattlesnake envenomation: prolonged neurotoxicity and rhabdomyolysis.

An 11-year-old girl presented to the emergency department with hypoventilation and shock after being bitten by a Mojave rattlesnake. Intubation was required, and she improved rapidly after fluid resuscitation and antivenom administration. She was extubated four hours after envenomation and did well. The patient subsequently developed increased weakness and cranial nerve paresis and required reintubation for respiratory failure at 30 hours after envenomation despite administration of 30 vials of antivenom. She improved after administration of additional antivenom and was extubated ten hours later. Twenty-four hours after envenomation, signs of rhabdomyolysis were noted with myoglobinuria and a creatine phosphokinase level of 96,400 units/L. Myoglobinuric renal failure was treated with mannitol, hydration, and alkalinization of the urine. The patient's renal and neurological functions improved steadily during the following three to four days. Neurotoxic and myotoxic effects of Mojave venom are known to occur but are not well documented in human beings. Recognition of potential complications from envenomation such as respiratory paralysis and rhabdomyolysis with myoglobinuric renal failure is critical.

Antivenins↗

Dobutamine pharmacokinetics and pharmacodynamics in pediatric intensive care patients.

OBJECTIVE: To evaluate the pharmacokinetics and pharmacodynamics of dobutamine in critically ill children. DESIGN: A prospective study of pediatric patients receiving continuous infusions of dobutamine in a stepwise format from 2.5 to 10.0 micrograms/kg/min. SETTING: A pediatric critical care unit. PATIENTS: Twelve children ranging in age from 1 month to 17 yrs with primary medical conditions. MEASUREMENTS: Plasma dobutamine concentrations and hemodynamic responses were measured at each infusion rate at steady state. Dose response data were analyzed to determine the threshold or minimum plasma dobutamine concentration necessary for discernible hemodynamic effects. MAIN RESULTS: Dobutamine plasma clearance rates ranged from 40 to 130 mL/kg/min. Each patient presented a linear increase in the plasma dobutamine concentration at each infusion rate (r2 = .97, p less than .001). Plasma clearance rate vs. actual dobutamine concentration did not vary. Cardiac output, BP, and heart rate increased 30%, 17%, and 7%, respectively, at maximal dose. The dobutamine concentration thresholds for changes in cardiac output, BP, and heart rate were 13 +/- 6, 23 +/- 14, and 65 +/- 30 ng/mL, respectively. CONCLUSIONS: There was no effect of plasma dobutamine concentration or infusion rate on plasma clearance rate. For this group of patients, over the range of the intravenous doses studied, dobutamine pharmacokinetics followed a first-order kinetic model. Threshold values for dobutamine usually show increases in cardiac output before changes in heart rate. These data demonstrate that dobutamine is an effective inotropic agent in critically ill pediatric patients and has minimal chronotropic action.

Blood Pressure↗